It a falling object starts at rest and ends at rest, then it gains all of its energy from gravity, and all of that energy is deposited in your unfortunate foot. Kinetic energy is (average) force times distance; whether you’re winding a spring, starting a fire (with friction), firing projectiles, or crushing your foot. The energy the object gains when falling is equal to its weight (the force of gravity) times the distance it falls. As a result, the stopping force required is proportionately larger. Something falling on your foot stops in about half a cm or a quarter inch, what with skin and bones that flex a little.